Precise Absolute Navigation: An Evaluation of PPS Position Management

摘要

This report demonstrates a method whereby the Precise Positioning Service (PPS)solutions recorded in the field can be reprocessed at a later time with precise ephemerides. The reprocessing with precise ephemerides improves the quality of the navigation solutions compared with the solutions obtained when the broadcast ephemerides are used. The Precise Absolute Navigation (PAN) algorithm described in this paper avoids the need to reprocess the Selective Availability-(SA-) corrected observations. However, the following are required: access to the SA-corrected broadcast ephemerides for the time of interest, the postfit precise ephemerides, the PPS navigation solutions to be corrected, the Global Positioning System (GPS) time of each solution, and a list of the satellites used. The PAN algorithm is described and its effectiveness tested with PP S-equivalent navigation solutions. The precise satellite ephemerides chosen for the navigation improvements are the DMA precise ephemerides and clock solutions. The true absolute position at each observation is either a given static point or was obtained from the on-the-fly (OTF) kinematic relative position solutions referenced to a known absolute point.